Impact of Share 35 liver transplantation allocation in Australia and New Zealand.

Patients with high model for end-stage liver disease (MELD) scores waiting for liver transplantation in Australia and New Zealand (ANZ) have had limited access to deceased donor livers and therefore binational sharing of livers, for patients with a MELD score ≥35 was introduced in February 2016. Waiting list mortality, post-transplant outcomes and intention-to-treat survival were compared between patients whose MELD score reached 35 on the waiting list between October 2013 and April 2015 (Pre-Share 35 group, n = 23) and patients who were Share 35 listed between February 2016 and May 2022 (Share 35 group, n = 112). There was significantly reduced waiting list mortality in share 35 listed patients in comparison to the pre-Share 35 group (11.7% vs. 52.2%, OR .120 95% CI .044-.328, P < .001). Post-transplant patient and graft survival were not significantly different between the groups (5-year patient survival 82% vs. 84%, P = .991, 5-year graft survival 82% vs. 76%, P = .543). Intention-to-treat survival was superior in the Share 35 group (HR .302, 95% CI .149-.614, P < .001). Introduction of Share 35 in ANZ resulted in a 78% risk reduction in waiting list mortality, equivalent post-transplant survival and an improvement in intention-to-treat survival.

Structural characterisation of nanoalloys for (photo)catalytic applications with the Sapphire library.

A non-trivial interplay rules the relationship between the structure and the chemophysical properties of a nanoparticle. In this context, characterization experiments, molecular dynamics simulations and electronic structure calculations may allow the variables that determine a given property to be pinpointed. Conversely, a rigorous computational characterization of the geometry and chemical ordering of metallic nanoparticles and nanoalloys enables discrimination of which descriptors could be linked with their stability and performance. To this end, we introduce a modular and open-source library, Sapphire, which may classify the structural characteristics of a given nanoparticle through several structural analysis techniques and order parameters. A special focus is geared towards using geometrical descriptors to make predictions on a given nanoparticle's catalytic activity.

Exploring AuRh Nanoalloys: A Computational Perspective on the Formation and Physical Properties.

We studied the formation of AuRh nanoalloys (between 20-150 atoms) in the gas phase by means of Molecular Dynamics (MD) calculations, exploring three possible formation processes: one-by-one growth, coalescence, and nanodroplets annealing. As a general trend, we recover a predominance of Rh@Au core-shell ordering over other chemical configurations. We identify new structural motifs with enhanced thermal stabilities. The physical features of those selected systems were studied at the Density Functional Theory (DFT) level, revealing profound correlations between the nanoalloys morphology and properties. Surprisingly, the arrangement of the inner Rh core seems to play a dominant role on nanoclusters' physical features like the HOMO-LUMO gap and magnetic moment. Strong charge separations are recovered within the nanoalloys suggesting the existence of charge-transfer transitions.

A systematic review of small for size syndrome after major hepatectomy and liver transplantation.

BACKGROUND: Major hepatectomy (MH) and particular types of liver transplantation (LT) (reduced size graft, living-donor and split-liver transplantation) lead to a reduction in liver mass. As the portal venous return remains the same it results in a reciprocal and proportionate rise in portal venous pressure potentially resulting in small for size syndrome (SFSS). The aim of this study was to review the incidence, diagnosis and management of SFSS amongst recipients of LT and MH. METHODS: A systematic review was performed in accordance with the 2010 Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. The following terms were used to search PubMed, Embase and Cochrane Library in July 2019: ("major hepatectomy" or "liver resection" or "liver transplantation") AND ("small for size syndrome" or "post hepatectomy liver failure"). The primary outcome was a diagnosis of SFSS. RESULTS: Twenty-four articles met the inclusion criteria and could be included in this review. In total 2728 patients were included of whom 316 (12%) patients met criteria for SFSS or post hepatectomy liver failure (PHLF). Of these, 31 (10%) fulfilled criteria for PHLF following MH. 8 of these patients developed intractable ascites alongside elevated portal venous pressure following MH indicative of SFSS. CONCLUSION: SFSS is under-recognised following major hepatectomy and should be considered as an underlying cause of PHLF. Surgical and pharmacological therapies are available to reduce portal congestion and reverse SFSS.

Keanu: a novel visualization tool to explore biodiversity in metagenomes.

BACKGROUND: One of the main challenges when analyzing complex metagenomics data is the fact that large amounts of information need to be presented in a comprehensive and easy-to-navigate way. In the process of analyzing FASTQ sequencing data, visualizing which organisms are present in the data can be useful, especially with metagenomics data or data suspected to be contaminated. Here, we describe the development and application of a command-line tool, Keanu, for visualizing and exploring sample content in metagenomics data. We developed Keanu as an interactive tool to make viewing complex data easier. RESULTS: Keanu, a tool for exploring sequence content, helps a user to understand the presence and abundance of organisms in a sample by analyzing alignments against a database that contains taxonomy data and displaying them in an interactive web page. The content of a sample can be presented either as a collapsible tree, with node size indicating abundance, or as a bilevel partition graph, with arc size indicating abundance. Here, we illustrate how Keanu works by exploring shotgun metagenomics data from a sample collected from a bluff that contained paleosols and a krotovina in an alpine site in Ft. Greely, Alaska. CONCLUSIONS: Keanu provides a simple means by which researchers can explore and visualize species present in sequence data generated from complex communities and environments. Keanu is written in Python and is freely available at https://github.com/IGBB/keanu .

Illuminating structural proteins in viral "dark matter" with metaproteomics.

Viruses are ecologically important, yet environmental virology is limited by dominance of unannotated genomic sequences representing taxonomic and functional "viral dark matter." Although recent analytical advances are rapidly improving taxonomic annotations, identifying functional dark matter remains problematic. Here, we apply paired metaproteomics and dsDNA-targeted metagenomics to identify 1,875 virion-associated proteins from the ocean. Over one-half of these proteins were newly functionally annotated and represent abundant and widespread viral metagenome-derived protein clusters (PCs). One primarily unannotated PC dominated the dataset, but structural modeling and genomic context identified this PC as a previously unidentified capsid protein from multiple uncultivated tailed virus families. Furthermore, four of the five most abundant PCs in the metaproteome represent capsid proteins containing the HK97-like protein fold previously found in many viruses that infect all three domains of life. The dominance of these proteins within our dataset, as well as their global distribution throughout the world's oceans and seas, supports prior hypotheses that this HK97-like protein fold is the most abundant biological structure on Earth. Together, these culture-independent analyses improve virion-associated protein annotations, facilitate the investigation of proteins within natural viral communities, and offer a high-throughput means of illuminating functional viral dark matter.

A novel immune function biomarker identifies patients at risk of clinical events early following liver transplantation.

Balancing immunosuppression after liver transplant is difficult, with clinical events common. We investigate whether a novel immune biomarker based on a laboratory platform with widespread availability that measures interferon γ (IFNγ) after stimulation with a lyophilized ball containing an adaptive and innate immune stimulant can predict events following transplantation. A total of 75 adult transplant recipients were prospectively monitored in a blinded, observational study; 55/75 (73.3%) patients experienced a total of 89 clinical events. Most events occurred within the first month. Low week 1 results were significantly associated with risk of early infection (area under the receiver operating characteristic curve [AUROC], 0.74; P = 0.008). IFNγ ≤ 1.30 IU/mL (likelihood ratio positive, 1.93; sensitivity, 71.4%; specificity, 63.0%) was associated with the highest risk for infection with minimal rejection risk. Nearly half the cohort (27/60, 45.0%) expressed IFNγ ≤ 1.30 IU/mL. Moreover, an elevated week 1 result was significantly associated with the risk of rejection within the first month after transplant (AUROC, 0.77; P = 0.002), but no episodes of infection. On multivariate logistic regression, IFNγ ≥ 4.49 IU/mL (odds ratio, 4.75) may be an independent predictor of rejection (P = 0.05). In conclusion, low IFNγ suggesting oversuppression is associated with infections, whereas high IFNγ indicating undersuppression is associated with rejection. This assay offers the potential to allow individualization and optimization of immunosuppression that could fundamentally alter the way patients are managed following transplantation. Liver Transplantation 23 487-497 2017 AASLD.

C-H activation reactions as useful tools for medicinal chemists.

In recent years, there has been an exponential rise in the number of reports describing synthetic methods that utilize catalytic sp3 and sp2 C-H bond activation. Many have emerged as powerful synthetic tools for accessing biologically active motifs. Indeed, application to C-C and C-heteroatom bond formation, provides new directives for the construction of new pharmaceutical entities. Herein, we highlight some recent novel C-H activation processes that exemplify the utility of these transformations in medicinal chemistry.

Targeted individual prophylaxis offers superior risk stratification for cytomegalovirus reactivation after liver transplantation.

Cytomegalovirus (CMV) can reactivate following liver transplantation. Management of patients currently considered low risk based on pretransplant serology remains contentious, with universal prophylaxis and preemptive strategies suffering from significant deficiencies. We hypothesized that a CMV-specific T cell assay performed early after transplant as part of a preemptive strategy could better stratify "low-risk" (recipient seropositive) patients. We conducted a prospective, blinded, observational study in 75 adult recipients. QuantiFERON-cytomegalovirus was performed both before and at multiple times after transplant. Low-risk patients (n = 58) were monitored as per unit protocol and treatment was commenced if CMV > 1000 copies/mL (DNAemia). Twenty patients needed antiviral treatment for other reasons and were censored (mainly for rejection or herpes simplex virus infection); 19/38 (50%) of the remaining low-risk patients developed DNAemia at mean 34.6 days after transplant. A week 2 result of <0.1 IU/mL was significantly associated with risk of subsequent DNAemia (hazard ratio [HR], 6.9; P = 0.002). The positive predictive value of 80% suggests these patients are inappropriately labeled low risk and are actually at high likelihood of CMV reactivation. A secondary cutoff of <0.2 IU/mL was associated with moderate risk (HR, 2.8; P = 0.01). In conclusion, a protocol based on a single early CMV-specific T cell based assay would offer improved risk stratification and individualization of patient management after transplant. This could offer improved drug and service utilization and potentially result in significant improvements over both currently used protocols to manage supposedly low-risk patients.

Design and synthesis of new tricyclic indoles as potent modulators of the S1P1 receptor.

Modulators of S1P1 have proven utility for the treatment of autoimmune disease and efforts to identify new agents with improved safety and pharmacokinetic parameters are ongoing. Several new S1P1 chemotypes were designed and optimized for potency and oral bioavailability. These new agents are characterized by a 'tricyclic fused indole array' and are highly potent agonists of the S1P1 receptor.

Discovery of 1a,2,5,5a-tetrahydro-1H-2,3-diaza-cyclopropa[a]pentalen-4-carboxamides as potent and selective CB2 receptor agonists.

The design and synthesis of novel 1a,2,5,5a-tetrahydro-1H-2,3-diaza-cyclopropa[a]pentalen-4-carboxamide CB2 selective ligands for the potential treatment of pain is described. Compound (R,R)-25 has good balance between CB2 agonist potency and selectivity over CB1, and possesses overall favorable pharmaceutical properties. It also demonstrated robust in vivo efficacy mediated via CB2 activation in the rodent models of inflammatory and osteoarthritis pain after oral administration.

Discovery of a novel trans-1,4-dioxycyclohexane GPR119 agonist series.

The design and optimization of a novel trans-1,4-dioxycyclohexane GPR119 agonist series is described. A lead compound 21 was found to be a potent and efficacious GPR119 agonist across species, and possessed overall favorable pharmaceutical properties. Compound 21 demonstrated robust acute and chronic regulatory effects on glycemic parameters in the diabetic or non-diabetic rodent models.

Prevalence of obstructive coronary artery disease in patients undergoing lung transplantation: case series and review of the literature.

BACKGROUND: Coronary angiography is commonly performed prior to lung transplantation, but its utility is unproven. METHODS: We conducted a single-center retrospective analysis of consecutive patients referred for coronary angiography as part of a pre-operative evaluation for lung transplantation and reviewed the literature for prior series. RESULTS: A total of 89 patients, 48 men and 41 women were included. Obstructive (≥70% stenosis) CAD was present in 9 (10%), non-obstructive (<70% stenosis) CAD in 24 (27%), and no angiographic evidence of CAD in 56 (63%) patients. We found 13 previously published series in the literature, in which a total of 1998 patients underwent coronary angiography pre-lung transplant. Together with our 89 patients, obstructive CAD was found in 11%. CONCLUSIONS: In conclusion, given the low prevalence of obstructive CAD in patients referred for lung transplantation, the inherent risk of angiography, and unproven benefit of detection of obstructive CAD, the utility of routine coronary angiography in this population requires validation in prospective studies.

Discovery and optimization of 5-fluoro-4,6-dialkoxypyrimidine GPR119 agonists.

A series of 5-fluoro-4,6-dialkoxypyrimidine GPR119 modulators were discovered and optimized for in vitro agonist activity. A lead molecule was identified that has improved agonist efficacy relative to our clinical compound (APD597) and possesses reduced CYP2C9 inhibitory potential. This optimized lead was found to be efficacious in rodent models of glucose control both alone and in combination with a Dipeptidyl peptidase-4 (DPP-4) inhibitor.

Computationally Driven Discovery of a BCR-ABL1 Kinase Inhibitor with Activity in Multidrug-Resistant Chronic Myeloid Leukemia.

The permeability glycoprotein, encoded by the ABCB1 gene, is widely implicated in multidrug resistance (MDR), as it has been shown to reduce the intracellular concentration of most small molecule therapeutics, including the majority of the breakpoint cluster region Abelson proto-oncogene 1 (BCR-ABL1) kinase inhibitors used in the treatment of Philadelphia chromosome positive (Ph+) leukemias. With this in mind, we describe an integrated theoretical and experimental approach to shed light on substituent effects in the pendant anilino moiety of 4-anilinoquinazolines and 4-anilinoquinoline-3-carbonitrile-based kinase inhibitors and their influence on P-gp-mediated efflux. This analysis culminated in the identification of a hydroxylamine-bearing, dual cSRC/BCR-ABL1 kinase inhibitor 16a that exhibits a marked reduction in P-gp-mediated efflux ratio and potent activity in a Ph+ patient-derived cell line (K562) and an MDR-Ph+ patient-derived cell line (K562/Dox) overexpressing P-gp. Overall, we demonstrate that the P-gp-mediated efflux ratio can be minimized by computationally driven optimization of the molecular dipole and/or cpKa without recourse to intramolecular hydrogen bonds.

Discovery of a Hydroxylamine-Based Brain-Penetrant EGFR Inhibitor for Metastatic Non-Small-Cell Lung Cancer.

Metastases to the brain remain a significant problem in lung cancer, as treatment by most small-molecule targeted therapies is severely limited by efflux transporters at the blood-brain barrier (BBB). Here, we report the discovery of a selective, orally bioavailable, epidermal growth factor receptor (EGFR) inhibitor, 9, that exhibits high brain penetration and potent activity in osimertinib-resistant cell lines bearing L858R/C797S and exon19del/C797S EGFR resistance mutations. In vivo, 9 induced tumor regression in an intracranial patient-derived xenograft (PDX) murine model suggesting it as a potential lead for the treatment of localized and metastatic non-small-cell lung cancer (NSCLC) driven by activating mutant bearing EGFR. Overall, we demonstrate that an underrepresented functional group in medicinal chemistry, the trisubstituted hydroxylamine moiety, can be incorporated into a drug scaffold without the toxicity commonly surmised to accompany these units, all while maintaining potent biological activity and without the molecular weight creep common to drug optimization campaigns.

Atypical N-Alkyl to N-Noralkoxy Switch in a Dual cSRC/BCR-ABL1 Kinase Inhibitor Improves Drug Efflux and hERG Affinity.

We describe an atypical amine bioisostere, the trisubstituted hydroxylamine, that upon incorporation into an approved dual cSRC/BCR-ABL1 kinase inhibitor yields 9, a compound that retains potent biological activity and couples it with improved drug efflux and hERG affinity at the expense of only a 2 atomic mass unit increase in molecular weight. Contrary to the common expectation for hydroxylamines in medicinal chemistry, 9 is well tolerated in vivo and lacks the mutagenicity and genotoxicity so often ascribed to lesser substituted hydroxylamines. A matched molecular pair (MMP) analysis suggests that the beneficial properties conferred by the N-alkyl to N-noralkoxy switch arises from a reduction in basicity of the piperazine unit. Overall, these results lend additional support to the use of trisubstituted hydroxylamines as bioisosteres of N-alkyl groups that are not involved in key polar interactions.